alert udp any 53 -> $HOME_NET any (msg:"ET MALWARE Win32.Zbot.chas/Unruy.H Covert DNS CnC Channel TXT Response"; content:"|C0 0C 00 10 00 01|"; content:"|00 dd dc|"; distance:4; within:3; content:!"v="; distance:0; content:!"p="; distance:0; content:!"spf2.0/"; content:!"spf1"; distance:0; content:!"|7c|"; distance:0; content:!"_domainkey"; classtype:command-and-control; sid:2013935; rev:8; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2011_11_21, deployment Perimeter, performance_impact Low, confidence Medium, signature_severity Major, updated_at 2019_07_26;)